(57) A fitting for joining a tube (10) to another axially aligned tube (12), or to a T-joint, elbow joint, or the like, comprising a sleeve (14a) fitted over the end of the tube, and an annular tubular member (16a) forced over the sleeve in coaxial relationship with the sleeve and the tube to compress the sleeve around the end of the tube to provide a high-strength fluid-tight joint between the sleeve and the tube. The fitting and the tube are formed of electrically conductive material, and an insulating dry lubricant is interposed between the components of the fitting, and between the fitting and the tube. The fitting is especially constructed to provide conductive paths from the surface of the tube and from the surface of an inner component of the fitting to an outer component so as to avoid arcing across the lubricant layer in the event of a lightning strike, or the like.